Derek's expecting the new guy. He's expecting another mostly-useless college kid who doesn't know one end of a horse from the other, and Derek doesn't have the time to babysit. What he's not expecting is Stiles Stilinski, who carries on conversations with the livestock and gets maybe a little too chummy with Isaac and is really kind of stupidly perfect in every way. And it's just distracting, that's all.

Derek's a dressage rider with a reputation for frowning and making people cry. Stiles is an acrobatic stunt rider whose resume includes medieval-themed dinner shows and the actual circus. Derek's an Olympian, he doesn't need this shit.